package com.heima.article.stream;

import com.alibaba.fastjson.JSON;
import com.heima.common.constants.HotArticleConstants;
import com.heima.model.mess.ArticleVisitStreamMess;
import com.heima.model.mess.UpdateArticleMess;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;
import org.apache.ibatis.annotations.Update;
import org.apache.kafka.streams.KeyValue;
import org.apache.kafka.streams.StreamsBuilder;
import org.apache.kafka.streams.kstream.*;
import org.checkerframework.checker.units.qual.K;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.time.Duration;

@Slf4j
@Configuration
public class HotArticleStreamHandler {

    @Bean
    public KStream<String, String> KStream(StreamsBuilder streamsBuilder)
    {
        // 接收消息
        KStream<String, String> stream = streamsBuilder.stream(HotArticleConstants.HOT_ARTICLE_SCORE_TOPIC);

        // 聚合流式处理
        stream.map((key, value)->{
            UpdateArticleMess mess = JSON.parseObject(value, UpdateArticleMess.class);
            // 重置消息的key和value
            return new KeyValue<>(mess.getArticleId().toString(), mess.getType().name()+":"+mess.getAdd());
        })
                // 根据文章id进行聚合
                .groupBy((key, value)->key)
                // 时间窗口
                .windowedBy(TimeWindows.of(Duration.ofSeconds(10)))
                // 自行实现聚合计算
                .aggregate(
                        // 初始方法, 返回值是消息的value
                        new Initializer<String>() {
                            @Override
                            public String apply() {
                                return "COLLECTION:0,COMMENT:0,LIKES:0,VIEWS:0";
                            }
                        },
                        // 真正的聚合操作, 返回值是消息的value
                        new Aggregator<String, String, String>() {
                            @Override
                            public String apply(String key, String value, String aggValue) {
                                if(StringUtils.isBlank(value)){
                                    return aggValue;
                                }
                                String[] aggAry = aggValue.split(",");
                                int col=0, com=0, lik=0, vie=0;
                                for (String agg : aggAry) {
                                    String[] split = agg.split(":");
                                    /**
                                     * 获得初始值, 也是时间窗口内计算之后的值
                                     */
                                    switch (UpdateArticleMess.UpdateArticleType.valueOf(split[0]))
                                    {
                                        case COLLECTION:
                                            col = Integer.parseInt(split[1]);
                                            break;
                                        case COMMENT:
                                            com = Integer.parseInt(split[1]);
                                            break;
                                        case LIKES:
                                            lik = Integer.parseInt(split[1]);
                                            break;
                                        case VIEWS:
                                            vie = Integer.parseInt(split[1]);
                                            break;
                                    }
                                }
                                // 累加操作
                                String[] valAry = value.split(":");
                                switch (UpdateArticleMess.UpdateArticleType.valueOf(valAry[0]))
                                {
                                    case COLLECTION:
                                        col += Integer.parseInt(valAry[1]);
                                        break;
                                    case COMMENT:
                                        com += Integer.parseInt(valAry[1]);
                                        break;
                                    case LIKES:
                                        lik += Integer.parseInt(valAry[1]);
                                        break;
                                    case VIEWS:
                                        vie += Integer.parseInt(valAry[1]);
                                        break;
                                }
                                String formatStr = String.format("COLLECTION:%d,COMMENT:%d,LIKES:%d,VIEWS:%d", col, com, lik, vie);
                                System.out.println("文章的id "+key);
                                System.out.println("当前时间窗口内的消息处理结果: "+formatStr);
                                return formatStr;
                            }
                        }, Materialized.as("hot-article-stream-count-001")
                )
                .toStream()
                .map((key, value)->{
                    return new KeyValue<>(key.key().toString(), formatObj(key.key().toString(), value));
                })
                // 发送消息
                .to(HotArticleConstants.HOT_ARTICLE_INCR_HANDLE_TOPIC);
        return stream;
    }

    /**
     * 格式化消息的value数据
     * @param articleId
     * @param value
     * @return
     */
    private String formatObj(String articleId, String value) {
        ArticleVisitStreamMess mess = new ArticleVisitStreamMess();
        mess.setArticleId(Long.valueOf(articleId));

        // COLLECTION:0,COMMENT:0,LIKES:0,VIEWS:0
        String[] valAry = value.split(",");
        for (String val : valAry) {
            String[] split = val.split(":");
            switch (UpdateArticleMess.UpdateArticleType.valueOf(split[0]))
            {
                case COLLECTION:
                    mess.setCollect(Integer.parseInt(split[1]));
                    break;
                case COMMENT:
                    mess.setComment(Integer.parseInt(split[1]));
                    break;
                case LIKES:
                    mess.setLike(Integer.parseInt(split[1]));
                    break;
                case VIEWS:
                    mess.setView(Integer.parseInt(split[1]));
                    break;
            }
        }

        log.info("聚合消息处理之后的结果为: {}", JSON.toJSONString(mess));
        return JSON.toJSONString(mess);
    }

}
